Method and Device for Manufacturing Brushes.
1) Field of the Invention
The present invention concerns a method and device for manufacturing brushes, whereby bundles of fibers are provided in a brush body.
2) Discussion of the Related Art
It is known that the fibers of brushes can be finished at their free ends.
A traditional finishing consists in rounding off the far ends of the fibers, among others to prevent them from having sharp edges. This is particularly important when manufacturing tooth brushes, in order to prevent that, when using the obtained tooth brushes, the gums would be hurt by the sharp edges.
It is known that the rounding off can take place after the bundles of fibers have already been placed in the brush bodies. However, this technique is disadvantageous in that the rounding-off process is not optimal when fiber bundles of different lengths are being used and when fiber bundles which have not been cut off straight are being used, since not all the fiber bundles will make contact with the grinding tool used for the rounding off in the same manner in this case.
In order to remedy this, it is also known to first form bundles of fibers which have to be provided in a specific brush body, and to first process the far ends of these fibers, before placing them in the brush body. The fiber bundles can then, as they are provided in a holder, be mutually positioned such that they can all be optimally presented to a processing tool. The same applies to the fibers of one and the same bundle.
In the case of the latter technique, the fiber bundles are clamped in the holder while being finished by means of special clamping means, for example as described in EP 0,346,646. However, this technique is disadvantageous in that the holders have to be made rather complex, since also clamping means and drive means have to be provided to these holders, which are usually relatively small.
Further, it is also known to first lead fibers through a special device in order to round them off, after which they can be further processed in any way whatsoever. An example thereof is known from EP 0.674.862, whereby bundles of fibers are separated from a fiber stock by means of a holder in the shape of a rotating bundle remover and temporarily stay in this holder to be subsequently, after a certain rotation of the bundle remover, supplied again to a cartridge. During the rotation, the fibers pass along a device for rounding off the fiber ends. In EP 0.674.862, this device is schematically represented and no explanation is given as to whether the fibers are either or not clamped in particular. In reality, the fibers are indeed clamped in particular with a relatively large clamping force, by means of special clamping means. In practice, such a device is relatively complex as extra clamping means are required.